Hazards (Wildfires) Flashcards Preview

AS Geography - Abbi > Hazards (Wildfires) > Flashcards

Flashcards in Hazards (Wildfires) Deck (15)
Loading flashcards...
1

Distribution of wildfires

Requires a combination of dry vegetation and lightning strikes. Semi-arid climates (Mediterranean & Savanna). USA, Australia, Canada, Southern Europe.

2

Three type of wildfires

- Ground fire: beneath the roots and surface peat
- Surface fire: leaf litter and low lying vegetation
- Crown fire: tree canopy

3

Human ignition sources

- Accidental (bonfires)
- Arson

4

Natural ignition sources

- Lightning without much rain
- Electrical storms
- Volcanic eruptions

5

How does vegetation type affect wildfires?

Thick vegetation allows fire to spread quickly. Flammable oils from certain plants cause plants to burn quicker.

6

How do fuel characteristics affect wildfires?

Fine, dry vegetation causes fire to spread quicker but thick, dense vegetation causes it to burn more intensely.

7

How does El Nino/La Nina affect wildfires?

El Nino (warmer phase): provides warmer, wetter weather to grow vegetation.
La Nina (cold phase): provides colder, drier weather to dry out vegetation

8

How does climate change affect wildfires?

Temperature increases cause an increase in wildfires and wildfire season length.

9

How does topography affect wildfires?

Fire spreads faster on hills as heat rises.

10

Short term responses to wildfires

- Firefighting: water, chemicals or retardants
- Diverting flames from settlements: bulldozing areas of vegetation, beating flames
- Evacuation
- Spraying water onto roofs

11

Prevention to reduce risk during wildfires

Educating on home safety and fire safety

12

Preparedness to reduce risk during wildfires

Emergency plans e.g. warning systems for potential risk factors

13

Mitigation to reduce risk during wildfires

Controlled burning of flammable material and creating fire breaks

14

Adaption to reduce risk during wildfires

Using non-flammable, non-toxic materials when building. Urban planning (more gaps between buildings)

15

Prediction to reduce risk of wildfires

Computer simulations to predict fire behaviour